Porous filter



C. G. VOKES POROUS FILTER May 27, 1952 3 Sheets-Sheet 2 Filed Oct. 25, 1946 IN VENTOR dean. s. voxzs AttY y 27, 1952 c. G. VOKES 2,598,322

POROUS FILTER Filed Oct. 25-, 1946 3 Sheets-Sheet 5 I NVEN T R deal 6. yoKEs Patented May 27, 1952 POROUS FILTER Cecil Gordon Vokes, Guildford, England, assignor to Vokes,Limited, Guildford, England, a British company Application October 25, 1946, Serial No. 705,555

In Great Britain December 3, 1945 Claims. 1

This invention relates to filtering units of porous material of the kind described and claimed in Patent No. 2,448,930 to Edward Arthur Stokes for Porous Filter.

According to the present invention, a filtering unit comprises a tubular element of porous material having spaces in the tube wall filled with the same material in skeleton form and integral with the material of the wall.

From another aspect, the invention provides filtering apparatus including a filtering element constituting a tube of porous ceramic material, the tube wall having a hollow in communication with the clean side of the element and formed in the hollow a skeleton filling or reinforcement of the same material as and integral with the wall of the tube.

The tubular filtering element may be formed by a method which includes inserting a suitable foraminated spacing layer between two layers of ceramic material in plastic state, moulding the element with the spacing layer in position so as to produce a filling of the interstices in the spacing layer of the plastic ceramic material integral with that of the two layers and removing the spacing layer by heat.

Other parts of the invention are embodied in the typical forms of filter which will now be described with reference to the accompanying drawings in which:

Fig. 1 is a cross section of one form of filter,

Fig. 2 is a section on the line IIII of Fig. 1,

Fig. 3 is a cross section of another form of filter, and

Fig. 4 is a section on the line IVIV of Fig. 3.

In the form shown in Figs. 1 and 2, the filter comprises a casing I having a cover 2 in which cover are provided an inlet 3 for fluid to be filtered and-an outlet 4 for filtered fluid. A drain plug 5 is provided in the bottom of the casing.

Mounted within the casing are the filtering elements which comprise two tubular elements 6, 6 of porous ceramic material arrangedone inside the other with a space between them. Each element is formed with a hollow space 1 in the tube wall which is filled with the same material in skeleton form and integral with the material of both the adjacent walls of this space 1' The tubes as shown are cylindrical and are arranged co-axially but obviously the tubes may be of other section or may be arranged noncoaxially if desired.

The tubular elements are formed by moulding from ceramic material with a suitable foraminous spacing layer between two layers of the ceramic material and then removing the spacing layer by heat. The spacing layer may be of material carbonising at a temperature not greater than that employed for kilning the ceramic material or of material having a melting point below the temperature which can be withstood without damage by the ceramic material.

The elements 6, 6' are supported by a spider 8 to which they are fixed by screwed rods 9 passing longitudinally throughthe wall of the element. The bottom edges of the elements engage annular recesses H1 in the spider, resting on joining rings H. The upper ends of the spaces 1 are closed by annular rings 22 of suitableimpervious material retained in position by'.the rods 9.

The spaces 1 in the walls of the elements are thus closed except for ports I2 in the bottoms of the recesses I0 which communicate with passages I3 in the spider leading to an axial passage M. This passage I4 is connected by a tube 15 to the outlet 4 in the cover 2.

The spider is supported from the bottom of the casing I by a spring [6 and is fixed to a spindle l1 passing through a gland [8 to the outside of the casing. A handle l9 isprovided on the spindle I! so that the tubular elements may be spring It, so that the filtering elements 6, 6',

coincide with the scrapers 20. The frame 2| surrounds the tube IE to locate the blades 20 .relative to the walls of the tubular filters 6, 6' and said frame is non-rotatively connected by a stud 25 with the cover 2 to prevent rotation of the blades 20.

Fluid to be filtered enters the casing I through the inlet 3, passes through the walls of the ceramic elements into the spaces 1 and from thence through the ports 12, passages I3 and tube 15 to the outlet 4. Impurities in the fluid will be deposited on the outsides of the tubular elements from which they can be removed by rotat-. ing the elements against the scraper blades. The elements 'are resiliently mounted to prevent damage to them by shock.

In the form shown in Figs. 3 and 4, a tubular filtering element, having spaces in the tube wall filled with the same material in skeleton form and integral with the material of the wall, is associated with a less fine filter element arranged in the same casing, the fiuid passing from a common inlet through the two elements to separate outlets. The mass of the fluid passes through the less fine element whilst a proportion of the fiuid passes through the. finer tubular elementand is'finely'filtered, so that the proportion of fine impurities in the whole of the fluid is reduced without the excessive back pressure that would result if the whole of the fluid was finely filtered.

The tubular filtering element-6 is" mounted in a casing I generally as described with reference to Figs. 1 and 2. The casing l is closed by a header 30 having an inlet 3|,an outlet 32 for fiuid passing through the tubular element'B-Jand an outlet 33 for fluid passing through the less fine element 34.

This less fine element-34 is of deeply pleated material *arranged between-top and bottom closure members '35 and -36 and :is' mounted coaxially withi-nthetubularelementfi:on the spider 8. The top closure member 35 is pressed against theend of'a sleeve 3''! in therheader 30, thezinterior of: this sleeve being in communication with thee-outlet 33. The :cl'osuremember35 may-have a cylindrical flange 4 I which protrudes into the interiorof the sleeve'3l.

ln'the-itop :closuremember 35 are"ports 38 whichiare normal'ly closed :by an annular valve member 29;:pressed against the inside of the top cldsurexmember 35 by aspring 49. The outer scraper blades 20 :maybe mounted directly on the; casing while the inner scraper blades 20 are carried by the: less finefil-terelement '34, said blades being mounted at their ends to the top and bottom closure members 35 and -35. A stud 5 extends upwardly from the top closure member 35'into a recess in the header- 39' to prevent rotation :of 'theinner blades 29.

Normally'fiuid passes from the inlets! into the casing l, partof this fluid passingth-roug-h the tubular elements-6" to the outlet 32 and-the remainder -(usually the greater part) passing fromzthe outside to the 'inside'of thesstar-shaped elementild and tothe :outlet 33. Should,.however, the element 34 become ficlogged and a back pressurergreater than a predetermined value be setup, the annularvalve-member 2-9=is forced dowma'gainst the, pressure. of the spring 4%) and fluid-passes; from the inlet 3 l t-hroughthe, ports 88; to theoutlets33 byf-passi-ng'the element- 34. The :passage of 1 fluid through the tubular elementfi is not "affected by the byepassi-ng of the element :34.

ilt will be understood that the. invention is not restricted 'to the details offthez-forms described by way er example which-may be'modifiedwithout ,.departing: from the broa-d idea underlying the invention.

I claim:

1.;Rl-ltering apparatus comprising a 'casing having a'headerinoludingan inlet and two outlets, la iitubular element :or porousmolded material having spaces in i the tube wall fitted with the 'same material ini-skeleton form and integral with "the material: of the'wallgsaid tubular elementzb'eing'. mounted within the=casing,-a spider supporting said tubular -.-'element and including passage means forconnecting the spaces int-the tube wall with one of therou-tlets-iromthehcasing, :a filter element less fine than thetubular element mounted. on.--said-spider interiorlyof. said tubular :element, a spring .-supporting said spider 'nected.

3. .A filter comprising a casing having an inlet and an outlet, a tubular filter element of molded porous material having a coarsely porous intermediate stratum between finely porous outer strata all of the same material and integrally united, a spider in said casing supporting the bot'tom of said filter element and having a drain channel open to said intermediate stratum of said filter element, means securing said tubular filter element on said spider and closing the top of said intermediate stratum to prevent direct ingress and egress, passage means from-said spider channel'to said casing outlet, a spindletfi'xed with said spider and depending. through saidfcas ing for rotation of said spidenfa-.springvinfsaid casing resilientlysupporting saidspid'errand biasing it upwardly, support means 1 interposed ibe tween said spider andthe top ofvsaidrcasinga and limiting the spring imposed movementcof said spider, 'means connecting said "support :sme'a'ns with said casing to prevent relative rotation therebetween,.and at least one scraperbladacarried 'by said: support means in' engagement with at least one'of the cylindrical walls of said. tubular filter. element'to scrape. said walls whenitlre spider is rotated by said spindle.

4. A filter as defined in claim 3 whereinr's'aid passagemeans comprises a tube centrallyi d'isposed in said casing. and engageable betweensaid casing and the .centerio'f said spider to'formuwith said :spindle a pivotal mounting for saidspi'der, said support-means surrounding.said tubato -10- cate: said scraper :blade relative to said tubular filter wall.

, 5. A filter as defined in .cla'imt3 wherein said support means comprises a .i-second filter 'iele ment that. is less fine than said tubular 'filter 'element; said casingrhaving a secondoutletuiniicommunication with :said second-filterlelemen't.

CECIL GORDON "VOKES.

-REFERENGES CITED "The following references are of record in the file of this patent:

- UNITED STATES PATENTS Number Name "Date 597,248 Rhood Jan. 11, 1898 730,485 Simoneton June 9, 181,107 1 Stewart Jan, 31, 1905 189,617 Linke 'May "9', -19 05 "803,238 Lynn "Oct. 31,:1'90 5 1;179,157 :Braun -1 .Apr. 11, 1916 1;652,173 La1or Dec. 13, 1927 2,276,118 .Taylor Mar. 1'0, 1942 2,301,120 i'Kamrath. ."Nov.?3, z.1 -'942 23781737 Simkovits June 19,: T 945 2,406,308 .Vokes etial. Aug. 20,:1946 2,448,930 Stokes Sept. 7, 1948 FOREIGN PATENTS Number Country Date 11,700 Great Britain .of =l-897 746,944 France Mar. 21, 1933 

